1. Field of the Invention
This invention relates to surface controlled subsurface safety valves used in oil and gas wells.
2. Description of the Prior Art
Surface controlled subsurface safety valves are commonly used in various types of wells to provide downhole protection if a failure or hazardous condition should occur at the well surface. U.S. Pat. No. 3,703,193 to George M. Raulins discloses a typical ball valve and equalizing mechanism used for this purpose. U.S. Pat. No. 3,826,462 to Frank H. Taylor discloses an alternative configuration for a subsurface safety valve. U.S. Pat. No. 3,865,141 to David E. Young discloses a flapper type subsurface safety valve which has a pressure equalizing system that enables reopening the valve after closure while minimizing the risk of damage to the flapper element and/or operating tube. The above patents are incorporated by reference for all purposes within this application.